CALIBRATION AND EXPERIMENTAL RESULTS OF A 2-DIMENSIONAL INTERFEROMETRIC RADIOMETER LABORATORY PROTOTYPE

In recent years, Earth observation by means of aperture synthesis radi ometry has received special attention by some space agencies as a poss ible solution to achieve high radiometric accuracy and spatial resolut ion at low microwave frequencies (L band), where the apparent brightne ss temperature is much more sensitive to soil moisture and sea surface salinity. This paper presents the characterization and calibration pr ocedure, as well as some synthetic images measured with an X band expe rimental Y-shaped Synthetic Aperture Interferometric Radiometer protot ype developed at the Polytechnic University of Catalonia. The instrume nt is composed of a single pair of antennas that can be moved along th e arms of an Y structure to synthesize a set of baselines. An experime ntal procedure is proposed to evaluate and then calibrate offset, inph ase, quadrature, and amplitude errors generated by receivers and corre lators.